Mar 05,2009 00:00
Peripheral arterial disease is a common circulatory problem affecting more than 8 million Americans. These days, the airwaves are loaded with multimillion-dollar marketing campaigns to lobby patients with the disease about what they need, what tests to receive and which drugs to take. One particular commercial urges patients with heart disease to screen for PAD, using the catchy tag line "we look for it; we find it; and we fix it."
Unfortunately, it's just not that simple. While it may be easy to identify PAD, determining who should be screened, when and how is much more difficult. What's more, "fixing it" is not that easy, either.
PAD results in the narrowing of the arteries that provide blood to the extremities. Typically, if a patient has significant narrowing in these arteries, it is likely that there are narrowed arteries throughout the body, including those that supply the heart, brain and kidneys. Luckily, physicians can identify PAD long before any symptoms are present simply by simultaneously measuring blood pressure in the arms and legs.
Determining the ratio of the ankle pressure to the brachial pressure can indicate the presence or absence of impaired blood flow, and it is a very sensitive measurement of cardiac risk. Normally, the ankle pressure is equal to or greater than the brachial. When the ankle pressure is 10 percent lower than the brachial, PAD is present and the risk of coronary artery disease or a heart attack is increased eightfold.
As a general rule, PAD symptoms only occur when the ankle blood pressure is 40-60 percent lower than the brachial pressure. In this case, patients experience pain in the calves and difficulty walking, which improves with rest. On examination, it is difficult to feel pulses in the ankles or feet; the skin looks shiny; there is little or no hair on the legs; and upon standing, the feet can become bright red. In these circumstances, further tests are needed to identify the severity of the blockages and determine whether symptoms can be improved by angioplasties or surgical procedures. Any procedure should focus exclusively on relieving symptoms or saving the leg.
Many hospitals and some cardiology practices now offer low-cost screening tests to identify the condition. If the disease is found, the patient's physician should be informed and an aggressive plan instituted to reduce the risk of heart attack and stroke. Long before it causes symptoms, PAD should be an urgent wake-up call to truly live a heart-healthy lifestyle and do everything you can to decrease your risk of a heart attack.
By improving diet and exercise, stopping smoking, treating high blood pressure, screening for and treating diabetes, and lowering cholesterol, patients with PAD can improve their conditions dramatically. In some circumstances, stress tests may be warranted to identify heart disease, and if any symptoms are present, more intensive evaluations, including angiograms, may be needed.
Unfortunately, when it comes to issues of the heart, it seems that many patients receive extensive work-ups that are not necessary or have no proven evidence of benefit. A patient who does not exhibit symptoms or sufficiently diminished ankle blood pressure often receives further testing, which can include a CT scan of the area from the abdomen to the lower limbs. This is particularly dangerous because of the high degree of radiation exposure, and if moderate blockages are identified, a specialist may recommend an angiogram to clarify the degree of blockage.
In many situations, angiograms are gateway procedures to more invasive and risky angioplasties. There is no scientific evidence that "fixing" narrowed arteries is of value in patients with mild cases of the disease and minimal symptoms.
For a patient with established heart disease or high risk of heart disease, screening for PAD is not necessary — especially if the patient follows a heart-healthy lifestyle. Unless symptoms of PAD are present, further work-up is of no added value.
However, screening for PAD can be a critical component in identifying risk of heart disease. Even if no significant symptoms of heart disease are present, the presence of PAD should be a serious alarm to take care of your heart. Be an empowered consumer of health care by avoiding needless, expense and inappropriate work-ups. Perhaps more than PAD, these tests can be seriously hazardous to your health.
Dr. David Lipschitz is the author of the book "Breaking the Rules of Aging”.Copyright 2009 Creators Syndicate Inc.